A). 1/2+1/4= (1X2)/(2X2)+1/4=2/4+1/4=3/4
B). 5/6+5/12= (5X2)/(6X2)+5/12=10/12+5/12=15/12
C). 13/14+5/7=13/14+(5X2)/(7X2)=13/14+10/14=23/14
D). 3/4+5/24=(3X6)/(4X6)+5/24=18/24+5/24=23/24
E). 6/7+2/35= (6X5)/(7X5)+2/35=30/35+2/35=32/34
F). 11/81+1/9=11/81+(1X9)/(9X9)=11/81+9/81=20/81
Voilà j’espère t’avoir aider !!!